Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
Known surgical graspers include an end effector that can be actuated to grasp tissue or other devices or objects. The end effector includes a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. The jaws can then be opened and closed to grasp and manipulate tissue. Some devices have end effectors that can be pivotally coupled to the shaft or a shaft that can be flexible relative to the end effector to allow the end effector to be angularly oriented to facilitate grasping of tissue. One drawback to such articulating devices, however, is that a mechanical linkage is used to transfer a force from a handle of the device to the end effector to activate the end effector. The mechanical linkage can interfere with the pivoted or curved orientation of the shaft, potentially causing it to straighten.
Accordingly, there remains a need for methods and devices for actuating and/or articulating a surgical grasper.